Preheat the oven to 425 F.In a large bowl, toss the sage leaves, rosemary and thyme branches, and parsley leaves together.With poultry shears, cut along each side of the the backbone of the turkey (and save for stock).Spread the turkey as flat as possible, skin side down on a clean surface; with a meat cleaver or large knife carefully cut through the entire breast bone of the turkey, creating two even-sized turkey breast halves with leg and wing attached. Or have the butcher do this.Rub 2 tablespoons of the butter evenly over all parts and under the skin of each turkey half and generously season all over with salt and pepper.Sprinkle the bottom of the roasting pan with 4 tablespoons of the herbs.Fit each turkey half into the pan. Add the garlic and cover with the remaining herbs.Roast the turkey uncovered on the lower third of the oven for 1 1/2 hours or until an internal temperature of 160 F is reached.Remove the turkey from the roasting pan and let rest covered for 20 minutes before serving.Strain the drippings from the roasting pan into a measuring cup, pressing the herbs and garlic into the strainer. Set aside and allow the drippings to separate.Dredge the giblets on a large dinner plate in 2 tablespoons of the flour.Melt 2 tablespoons of the butter in the bottom of the roasting pan over medium heat.Add the giblets and saute for 3 to 5 minutes or until golden and set aside.Melt the remaining butter in the roasting pan over medium heat until bubbly.Gradually whisk the remaining flour into the butter and stir until smooth and lightly brown.Separate the drippings from the fat and add only the drippings to the roux, whisking for two to three minutes or until thick and bubbly. Add half the stock into the flour and continue stirring until smooth.Add the remaining stock and let gravy reduce and thicken before adding the wine.Finely chop the giblets, stir in the cream, giblets, and hard cooked eggs (if using). Serve immediately.